Which item has shelf life of 5 years?

• A. Viton O-ring
• B. O-ring
• C. V-ring
• D. Gasket

Answer: (B)

Shelf life for elastomer seals is about how long they can be stored before aging affects performance. The standard O-ring is made from a common elastomer (often Buna-N/Nitrile) and is treated as the baseline for storage life. Under typical storage conditions, these materials can start to lose elasticity and may develop compression set or cracks after several years. Because of that, the maintenance guidelines assign a five-year shelf life to the ordinary O-ring to ensure reliability in seals and prevent failures in service.

Viton O-rings use a more resistant fluorocarbon material, which generally holds up better under heat and chemicals, so they usually have a longer shelf life than the standard O-ring. A V-ring is a different type of seal component, and gaskets vary widely in material and aging characteristics, so their shelf lives can differ from the five-year mark. The common convention for the generic O-ring is five years, which is why this item is the best answer.